Multi-band FM receiver for receiving FM broadcasting signals and TV broadcasting sound signals

Abstract

A multi-band receiver for receiving broadcast signals divided by frequencies into an FM group and a TV group, the TV group including at least two different frequency ranges separated by a substantial frequency gap. The receiver includes a band selector for selecting a desired frequency group from the two group, a tuning controller for selecting a desired broadcast frequency within the desired group from a predetermined tuning band, an oscillator for separating signals of the desired frequency from the received broadcast signals and converting the separated signals into audio signals and a frequency adjuster responsive to the band selector and the tuning controller for automatically adjusting the oscillation frequency of the oscillator when the TV group has been selected for substantially removing the frequency gap from the predetermined tuning band.

What is claimed is: 
     
       1. A multi-band receiver for receiving a plurality of broadcast signals having first and second groups of frequencies, the second group including at least two subgroups of frequencies separated by a fixed frequency gap, comprising: switch means for selecting one of said first and second groups;   tuning control means coupled to the switch means for selecting a desired frequency within the selected one of the first and second groups from a predetermined tuning band;   oscillation means having an oscillation frequency and responsive to said tuning control means for separating signals of the desired frequency from the received broadcast signals and for demodulating the separated signals into audio frequency signals; and   adjusting means responsive to the switch means and the tuning control means for automatically adjusting the oscillation frequency of the oscillation means when the second group has been selected to substantially remove the fixed frequency gap from the predetermined tuning band.   
     
     
       2. The receiver of claim 1 wherein the adjusting means includes means for varying the oscillation frequency of the oscillation means. 
     
     
       3. The receiver of claim 1 wherein the adjusting means includes a frequency divider having a dividing ratio, and means for changing the dividing ratio to set the oscillation frequency of the oscillation means. 
     
     
       4. The receiver of claim 1 wherein the adjusting means includes a programmable frequency divider and a phase comparator connected to the programmable frequency divider for setting the oscillation frequency of the oscillation means. 
     
     
       5. The receiver of claim 1 wherein the oscillation means includes a frequency converter, an amplifier coupled to the frequency converter, and a demodulator coupled to the amplifier, and the switch means includes means for controlling the volume of the audio signals. 
     
     
       6. A method for receiving a plurality of broadcast frequencies having first and second groups of frequencies, said second group including at least two subgroups of frequencies separated by a fixed frequency gap, comprising the steps of: manually selecting one of the first and second groups of frequencies;   manually selecting a desired broadcast frequency within the selected one of the first and second groups from a predetermined tuning band;   generating an oscillation signal having an oscillation frequency to separate signals corresponding to the desired broadcast frequency from the received broadcast signals and demodulating the separated signals into audio signals; and   automatically adjusting the oscillation frequency of the oscillating signal in accordance with the selected one of the first and second groups of frequencies and the desired broadcast frequency to substantially remove the fixed frequency gap from the predetermined tuning band at times when the switch means selects said second group.